Process for the reduction of stannic oxid.



UNITED STATES PATENT OFFICE.

ZDENKO METZL, OF ROUEN, FRANCE.

raoonss roarnn REDUCTION or STANNIC x113.

No Drawing.

To all whom it may concern:

Be it known that I, ZDENKO Mn'rzL, a subject of the Emperor of Austria-Hungary, residing at Rouen, in the Department of Seine-Inferieure, France, .have invented certain new and usful Improvements in Proeesses for the Reduction of Stannic Oxid, of

which the following is a specification.

The production of metallic tin from stannic oxid is mainly done in the trade by the dry process. The wet process is only employed for removing deleterious constituents of the tin ore. Attempts at carrying out a considerable time,w ereby considerable cost in fuel is involved. In addition the reduction is never a complete one and therefore is always connected with losses of material;

This invention has for its object the production of metallic tin by a reductive smelting with metallic zinc alone or mixed with other wellknown reducing agents. The preparatory purification of the tin ore for the reduction process is retained, but instead of carbon or carbonic oxid metalliczinc is employed as reducing medium, in consequence of the hitherto unknown circumstance that-stannic oxid is rapidly and quantitatively reduced bymetallic zinci p The principal advantage of the process consists in time and material being saved by the rapid and quantitative reduction, as it Specification of Letters Patent.

" Application filed mama 1c, 1912. Serial No. 684,334.

Before the tin offers no difficulties to arrange the apparatus even on a large scale in such a way that losses of the reducin medium and-of the final product are avoided.

Metallic zinc is melted as far as possible under exclusion of air or in' a ,reducin Patented Feb. 18, 191 3.

mosphere and the stannic oxid is intro uced into the bath of. zinc, the reduction taken place according to the following formula: Sn0 +2Zn=Sn+2ZnQ The reducing smeltin maybe carried out in crucibles or in tubular, muflle, reverberato or shaft furnaces, the resulting oxid of awe being volatilized and again reduced to zinc by means of carbonin a manner well known in the smelting industry, which zinc may again be employed for reducing fresh quantities of stannic oxid.

Any solid or aseous material may be em ployed as fuel or the reduction, so far as they partially assist the reduction process.

The recovery of the metallic tin may also be done by igniting a mixture. of stannic oxid and metallic zinc in a pulverulent form or in shavings and'with or without the addition of an igniting compound, after the 'manner' of Goldschmidts thermit process and in this way starting the desired reaction and reduction.

What I claim is 1. A process of reducing tin oxid to metallic tin, which com rises reacting upon the tin oxid with meta ic zinc at a temperature at least as high as the melting point of metallic zinc. I

2. A process of reducing tin oxid to metallic tin, which comprises reacting upon the tin oxid with metallic-zinc at a temperature at least as hi h as the melting point of metallic zinc, t on volatilizing the zinc oxid, treating the same with a reducing, agent, at a temperature capable of reducing the same to metallic zinc, and treating such zinc with tin oxid.

3. A process of reducing tin oxid which comprises mixing; together tin oxid and mewill propagate itself throughout the entire tallic zinc, in about the proportions expressed mass of material. 10 by the reaction In testimony whereof I affix my signature I in presence of two witnessea Q71 v v -rt Oily +AJl1kjl1"fit1l9; ZDENKU METZL then heating a small part of the mixture to "VVitnesses: a temperature capable of oauslng the said CHARLES TI-IORN,

reaction to take place, whereby the reaction MAUmcF, DANJOU. 

